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Otago Daily Times, Issue 8456, 1 April 1889, Page 2

MR M«KAY'S .REPORT]

(Bf Our Own Cobbespondene), Wellington, March 301 The preliminary report of Mr A. M'Kay* assistant geologist,' on the tin deposits o£*

Stewart's Island has just readied the Minister

of Mines. A general description 33 given of the

country in the vicinity of" Porfc Pegasus, where

the tin has hitherto been found,

states that in the. lower part of the vallej gold

was formerly found, but not in payable qn»n-» tity, and it proved particularly difficult to save owing to the presence of what was supposed to. be black sand, but which is now known to be

"stream tin." The "wash' in the face of thei old gold washings was only 12in.or 14in, and He M'Kay wa3 told that a dishful of this wash only yielded about half an ounce of tin, so that unless the stuff could ha rapidly turned over and disposed of this ground would not pay for washing. Higher up on thei eastern side ofthe middle basin the wash every-, where appears too thin to pay unless ifc is much richer in tin than is reported to be the case. On. the western side the wash is thicker, and on the Tasmanian claim it is said to be fully 6ft thick, yielding good prospects of tin. In same parts of the flat the wash is alleged to be 13ft thick, but this is not yet proved. The upper basia waa prospected without success. The east branqh of Pegasus creek shows fairly good wash, 2ft ta 4st thick, yielding fairly. Stream tin was also. -.. found at the survey camp to the south-west of the southern end of the "Tin Range," ail an elevation of 570 ft above sea _ level. This is not in direct communication with this gravel in the neighbourhood of the creek, but. * seems part of the gravel stratum covering the greater part of the table land. The tin here ia not associated with gravel sand. Ifc is coarserin grain and a clean sample. The wash,, how* ever, is only a foot thick, and the prospects seldom exceed half an ounce of tin per 'dish.. There was no time to make a fnll examination; of the eastern side of the tic range, but the prospects were better along the South creek than Pegasus creek".. Stream tin : is widely distributed on the low* ground and table land near Pegasus and .South,creeks; but Mr ©Kay fears that, the -wash is. too thin to pay for working. He admits that the general belief is otherwise,: bob he bases h^ views on the relative values of tin. aad gold. The deposits of lode tin are confined to a a small area-at the south end of the tin range, but he thinks thafc others may yet be found. As. yefc there is no' information tending to prove thafc tin lodes exist in the granite which pre-, vails there. The rocks constituting the tio, range where alone tin ore has yet been found in situ- are massive beds of quartzose and miqp. These have. : been mistaken for true fissure, reefs. Iron tungstate, which is apt to. be mistaken for tin, * abounds in the range, but so far as Mr M'Kay could learn tin has been found only near the south end, and in only two places has any work been done towards proving the character of the sapposed lode. The tin-bearing bed is a narrow rib ol quartz.in soft mica rock. There are three bands of quartz, bufc Mr M'Kay could only see tin or iron-tungstate in one. of them, which .does not average; more than Sin in thickness, and is often only an inch and a-half..' Eastward of this he saw an. elliptical disconnected mass of quartz parted from the rib and completely enclosed in mica ' rock, and this gave the best specimens that ha saw anywhere in the field. An opening lias been made in this only, to procure specimens, and the work has been abandoned., Further ' to the south-west three, bands of quarts all carry tungstate and tinj- -and the middle one,, which is the most productive in tin, has the thickness of 12in. Towards the eastern end the samples are ho richer than in the. northern quarry, and it has been only because of the greater thickness of the quartz band that a greater bulk ot ore has been got here. -, The tin bearing ribs of quartz are mere" segratipns in the mica. As to the paying prospects Mr M'Kay saya that, more must, be done before he can pronounce decidedly, but he is confident that tin ore will continue to be found both to the dip and along the eastern side of the range from the southern quarry to the northern outcrop in Black's lease, and he,sees no. reason to thinkthat tin is absent from the middle and northern parts of the tin range, or from fche lower partof Pegasus creekoh Todd and Harvey's freehold. From the considerable abundance a though perhaps nofc ih paying quantities, and the wide distribution of stream tin along Pegasua creek and the east of the maiu watershed of the island,-Mr M'Kay infers that other and richer deposits may yet be found hi situ ; and while he thinks that work should not be discontinued among the quartzose and mica rocks of the tin range, the granite and gneissic rocks to the east* ward and westward should be carefully searchedi especially the felspar and quartz veins, which, abound in more parts of the granite areas.